[BEIJING] Researchers who analysed samples from a patient who allegedly died of SARS in November 2003 say he may in fact have died of an infection with the H5N1 bird flu virus — two years before the government officially reported its first human case of the disease.

China reported its first outbreak of H5N1 in poultry in January 2004 and did not report a human infection until two years later in November 2005. 

The 24-year-old man from an unidentified city suffered from pneumonia and respiratory distress, and died four days after being hospitalised. He was diagnosed as a sporadic case of SARS (severe acute respiratory syndrome) based on his clinical symptoms.

But in last week's New England Journal of Medicine (22 June) eight researchers say they found no SARS virus when they analysed tissue samples from the patient.

Instead, they found H5N1 virus in samples from his lungs.

In an additional twist to the intrigue, last Wednesday (21 June) the journal said it had received an email from one of the authors, Wu-Chun Cao of the State Key Laboratory of Pathogens and Biosecurity in Beijing, asking them to withdraw the paper.

On Friday, Cao denied having written or sent the email.

The researchers were unavailable for interview, but two of them had mentioned the findings to SciDev.Net during a meeting held in April this year. 

Roy Wadia, a spokesperson for the World Health Organization's Beijing office, told SciDev.Net that the organisation has asked the Chinese Ministry of Health to investigate the case and report back.

"What is important is to know whether there are any more human cases than we have learned," Wadia says.

So far, the Chinese Ministry of Health has not commented on the research. Officially, the country has reported 19 human bird flu cases, including 12 deaths, to the World Health Organization.

In their paper, the researchers say the patient's strain of H5N1 was "genetically distant from viruses previously isolated from humans".

They say this genetic variation supports the approach of developing different vaccines for different regions, according to the genetic make-up of the virus in each region.

Link to full paper in New England Journal of Medicine

Reference: New England Journal of Medicine 354, 2731 (2006)